Here's the deal.. After not riding for a few years after starting a family I have jumped back in this year.. My main bike is a Trek 5900 I bought brand new in 2001.It's very well equipped and gets the job done. My back up bike is a 99 Raliegh R700 which I have had since new also. The drive train is shot, but the wheels which are Mavic CXP 33's on Ultegra hubs are good.. Is it worth upgrading the group to new 105?I want this bike to ride from November to March, it just needs to be a solid beater bike. I figure a new 105 bike would be at least $1,500 and new upgrades would save some money over that. Thanks in advance for any replies.